Patent US631445A successfully refreshed from Google Patents.
Patent US266052A successfully refreshed from Google Patents.
Patent US5620739A successfully refreshed from Google Patents.
US5620739A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thin film capacitors on gallium arsenide substrate and process for making the same
Assignee: Panasonic Holdings Corp
•
Filing: 1994-03-17
•
Granted: 1997-04-15
•
Expires: 2014-03-17
Abstract
Abstract A silicon nitride barrier layer is deposited on a gallium arsenide substrate to prevent evaporation of the substrate in subsequent heating steps. A silicon dioxide stress reduction layer is deposited on the barrier layer. A first electrode is formed on the stress reduction layer, then a liquid precursor is spun on the first electrode, dried at about 400 DEG C., and annealed at between 600 DEG C. and 850 DEG C. to form a BST capacitor dielectric. A second electrode is deposited on the dielectric and annealed.
Inventors
- 👤 Masamichi Azuma
- 👤 Carlos A. Paz de Araujo
- 👤 Michael C. Scott
- 👤 Toshiyuki Ueda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 18:35
CPC Classifications
H; H10; H10P; H10P14/00; H10P14/60; H10P14/63; H10P14/6326; H10P14/6342; B; B05; B05D; B05D1/00; B05D1/60; B05D3/00; B05D3/04; B05D3/0493; C; C23; C23C; C23C18/00; C23C18/02; C23C18/12; C23C18/1204; C23C18/1208; C23C18/1216; C23C18/1225; C23C26/00; C23C26/02; C30; C30B; C30B29/00; C30B29/60; C30B29/68; C30B7/00; H10B; H10B53/00; H10D; H10D1/00; H10D1/60; H10D1/68; H10D1/682; H10D1/684; H10D1/692; H10N; H10N30/00; H10N30/01; H10N30/07; H10N30/074; H10N30/077; H10N30/80; H10N30/85; H10N30/853; H10N30/8536; H10P14/66; H10P14/668; H05; H05K; H05K3/00; H05K3/10; H05K3/105; H10P14/69; H10P14/692; H10P14/6938; H10P14/69398
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
166 words
A method of fabricating a high capacitance thin film integrated circuit capacitor device, said method comprising the steps of: providing a gallium arsenide substrate; forming a barrier layer on said substrate; forming a first electrode; providing a metalorganic liquid precursor comprising barium, strontium, and titanium metals in effective amounts for yielding a solid dielectric barium strontium titanate upon treating of said liquid precursor; applying said liquid precursor on said first electrode; treating said liquid precursor on said first electrode to form a thin film of said barium strontium titanate, wherein said treating step includes a step of annealing a dried form of said liquid precursor on said first electrode at a temperature ranging from 600° C. to 850° C. for a time ranging from one minute to ninety minutes to provide an essentially flat capacitance in said barium strontium titanate at frequencies within the interval from 0.1 to 0.2 gigahertz; and forming a second electrode on said barium strontium titanate to complete said integrated circuit capacitor.
Claim 2
Independent Claim
166 words
A method of fabricating a high capacitance thin film integrated circuit capacitor device, said method comprising the steps of: providing a gallium arsenide substrate; forming a barrier layer on said substrate; forming a first electrode; providing a metalorganic liquid precursor comprising barium, strontium, and titanium metals in effective amounts for yielding a solid dielectric barium strontium titanate upon treating of said liquid precursor; applying said liquid precursor on said first electrode; treating said liquid precursor on said first electrode to form a thin film of said barium strontium titanate, wherein said treating step includes a step of annealing a dried form of said liquid precursor on said first electrode at a temperature ranging from 600° C. to 850° C. for a time ranging from one minute to ninety minutes to provide an essentially flat capacitance in said barium strontium titanate at frequencies within the interval from 0.1 to 0.2 gigahertz; and forming a second electrode on said barium strontium titanate to complete said integrated circuit capacitor.
Claim 3
Dependent Claim
30 words
A method as in claim 1 and further comprising the step of forming a stress reduction layer between said steps of forming a barrier layer and forming a first electrode.
Claim 4
Dependent Claim
14 words
A method as in claim 2 wherein said stress reduction layer comprises silicon dioxide.
Claim 5
Dependent Claim
17 words
A method as in claim 3 wherein said silicon dioxide layer is of about 1000 Å thickness.
Claim 6
Dependent Claim
16 words
A method as in claim 1 wherein said barrier layer comprises Si 3 N 4 .
Claim 7
Dependent Claim
18 words
A method as in claim 5 wherein said Si 3 N 4 is of about 1500 Å thickness.
Claim 8
Dependent Claim
44 words
The method as in claim 1 wherein said step of applying comprises placing a coat of said liquid precursor on said first electrode in a sufficient amount to provide a thickness of less than about 1000 Å of said barium strontium titanate per coat.
Claim 9
Dependent Claim
34 words
A method as in claim 8 wherein said step of treating comprises heating said precursor on said electrode to a temperature of from 200° C. to 500° C. prior to said step of annealing.
Claim 10
Dependent Claim
30 words
A method as in claim 8 wherein said step of treating comprises heating the precursor on said electrode to a temperature of about 400° C. in air or nitrogen gas.
Claim 11
Dependent Claim
21 words
A method as in claim 1 wherein said step of annealing includes said temperature ranging from 600° C. to 700° C.
Claim 12
Dependent Claim
21 words
A method as in claim 1 wherein said step of annealing includes said temperature ranging from 600° C. to 650° C.
Claim 13
Dependent Claim
26 words
A method as in claim 1 and further including a second anneal of said barium strontium titanate for a time between 1 minute and 90 minutes.
Claim 14
Dependent Claim
44 words
A method as in claim 1 wherein said step of treating comprises drying said precursor and further including the step of repeating said steps of applying and drying said precursor two or more times until said barium strontium titanate has obtained a desired thickness.
Claim 15
Dependent Claim
23 words
A method as in claim 1 wherein said barium strontium titanate has the formula Ba 0 .7 Sr 0 .3 TiO 3 .
Claim 16
Dependent Claim
13 words
A method as in claim 1 wherein said precursor comprises a metal alkoxycarboxylate.
Claim 17
Dependent Claim
14 words
A method as in claim 15 wherein said precursor further comprises a metal alkoxide.
References Cited (Backward Citations)
US5217754A
Cited
US5046043A
Cited
JPH0250973A
Cited
US4963390A
Cited
JPH02239103A
Cited
US5198269A
Cited
US5122923A
Cited
US5122477A
Cited
US5160762A
Cited
US5271955A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2000-04-14 | 2000-10-14 | 2001-04-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-04-14 | 2004-10-14 | 2005-04-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-04-14 | 2008-10-14 | 2009-04-15 | $7700.00 | Window Closed / Lapsed |